In a large skillet set over medium-high heat, sauté the onions in a drizzle of oil for 2-3 minutes, until soft. Add the garlic and ginger and cook for another minute.
Add any firm veg you're using, such as potatoes or cauliflower, and cook them for a few minutes, until they soften and start to turn golden on the edges. Add the remaining vegetables along with the curry paste, cumin, salt and coconut milk and bring the mixture to a simmer. Stir in the chutney, if you're using it, and cook for about 5 more minutes, until the sauce thickens and the vegetables are tender. (How long you cook it all will depend on the veg you use and how big the pieces are.)
Season with salt and pepper. Stir in the spinach and cook for a minute, just until it wilts.
Serve immediately over rice with chopped peanuts and/or cilantro sprinkled on top.